Adjustable pitch propeller



Aug. 2, i949. El ROUSE 2,477,944

ADJUSTABLE FITCH PROPELLER v j Filed July 19, 1947 2 Sheets-Sheet 1 I INVENTOR EDWARD H.ROUSE ATTORNEYS Aug. 2, 194%?. v E. H. Rouse 2,477,944

ADJUSTABLE PITCH PROPELLER Filed July 19" 1947 2 sheets-sheet 2 F l G. 4 46 5| le 4a@ multim 3? nl"I "Plum" 47a A mlllll 23 46 ATTORNE s fective. f- Other objects Patented Aug. 2, 1949 UNITED sTATEs PATENT OFFICE ADJUSTABLE PITCH PROPELLER Edward H. Rouse, Minneapolis, Minn.

Application July 19, 1947, Serial No. 762,046

My invention relates to adjustable pitch propellers and has for an object a propeller which canbe easily adjusted.

Another object 4of the invention resides in constructing the propeller with a hub having a blade pivoted thereto, the pivot for said blade being disposed so that swinging of the blade changes the pitch of the same and in providing an adjusting member therefor situated at the rear end 1of the blade and readily accessible for manipulaion.

yAnv object of the invention resides in mounting said adjusting member'for rotation about the axis of said hub.

A' stillfurther object -of the invention resides in constructing the blade witha part movable radially upon swinging of the blade and in providing the adjusting member with a juxtaposed part adapted to be engaged by the radially movable part of the blade to limit the swinging movement of the blade.

Another object ofthe invention resides in providing one ofy said parts with an abutment and the other of said parts with a number of stops, each stop being located a different distance from the axis of the hub and preferably in the form of a spiral, said stops upon rotation of the adjusting member being adapted to be separately broughtfinto position for engagement with said abutment.'

An object of the invention resides in providing yieldable locking means for holding the adjusting member inadjusted position.

A still further `object of the invention resides in providing a driven shaft on which said hub is mounted and in constructing said adjusting member in the form of a collar rotatable thereon.

A feature of the invention resides in providing locking -means for said collar including engageable teeth on said collar and hub for holding the collar in Aadjusted position, and in further providing resilient means acting between said shaft and collar for urging said teeth'into engagement.

Another object of the invention resides in rotatably mounting said hub on said shaft and in providingreleasable driving means between said shaft and hub and including a driving element and a driven element having facing surfaces formed'with engageable teeth thereon.

vAn object of the invention resides in utilizing the spring employed in connection with the locking means for; rendering said driving means-.ef-

v of :the invention reside in the novel combination and arrangement of parts and s claims. (o1. 17o-135.75)

2 in the details of construction hereinafter illustrated and/or described.

In the drawings:

Fig. 1 is a longitudinal elevational part-sectional view of a propeller and a portion of a propeller shaft illustrating an embodiment of my invention.

Fig. 2 is a rear end view of the structure shown in Fig. 1 with portions of the same broken away to illustrate the construction of the propeller.

Fig/3 is a perspective view of the parts of the invention separated from one another and shown partly in section.

Fig. 4 is a cross-sectional view taken on line 4-4 of Fig. 1. Y

Fig. 5 is a View similar to Fig. 4 showing the parts in altered position.

Fig. 6. is a view similar to Figs. 4 and 5 showing the parts in still dilerent positions.

Fig. 7 is a cross-sectional view taken on line 1-1 of Fig. 1.

In the use of out-board motors, it has been found that the propeller operates most efficiently with the blades set at a certain pitch. This pitch varies for different load conditions and speeds. In addition, it has been found that propellers frequently strike submerged objects and that .the usual shear pins employed therewith are broken thus necessitating removal of the propeller and installation of a new pin. Devices for overcoming these dilhculties require a considerable amount of space making a clumsy and awkward construction and in the case of adjustment of the pitch of the propeller, necessitate swinging out the blades before the .adjustment can be made. The instant invention provides a construction whereby both of the problems involved may be solved with a simple and compact construction which may be easily adjusted.

' The propeller illustrated is indicated in its entirety by the reference numeral I0 and comprises two blades II and Ila pivoted to a hub I3. The propeller Ill is mounted upon a propeller shaft I 4-which is driven from the motor through gearing-or other transmission elements such asl are well known in the art and which are not shown in the drawings. The various parts of the structure shown will now be described in detail.

The shaft I4 has a uniform diameter throughout the intermediate portion I2` of its extent and is formed with a reduced portion I5 at the rearward end of the same whichis threaded to receive a nut I6. The hub I3 has a boss I9 formed on it and which is provided with a bore I1of such dimensions as to provide a bearing for rotatably 3 and slidably supporting said hub on the portion I2 of shaft I4. The hub I3 is constructed with two lugs I8 and I8a which are disposed on opposite sides of the boss I9.

Inasmuch as both blades II and I Ia, are of the same construction, only the blade II will be described in detail. However, the same reference characters to which the suffix a have been added will be used to designate the corresponding parts. The .blade I'I is shown in detail in Fig. 7 and is constructed with a yoke 2| extending partly about the boss I9 and straddling the lug I8. This yoke includes two arms 22 and 23 which are disposed on opposite sides of 'saidlug A pin 24 extends jointly through said arms and through said lug I8 and serves to pivot the blade for swinging movement from a position such .as shown in full lines in Fig. 1 to a position as shown in dotted lines in said gure. As the blade `moves from one position to the other, the pitch of said blade variesand by limitingthe position to which the said blade may swing, :the pitch .at-which the blade operates can be determined.

For the purpose of eiecting a drive between the shaft I4 and the hub I3, areleasableclutch 25 is employed. This .clutch vzincludes a driving element 25 and a driven element 21. The latterelement isformed as part of the hub I3 being .in the nature of a skirt extending forwardly from .the boss LISrthereof. 'This skirt has a conical surface `28 which is 'formed with a lnumber of radially yeX- tending iteeth 29. 'fllhe driving element 26 is in the form of a figure of revolution havingr a-conical surface 3i :adapted .to engage 'the surface '28 of the element 21. This surface has forme'dlthereon, a `numberrof teeth `32 whichare adapted to lmesh With the teeth 29 when the element 2.6 is urged against the element Y1. 'The element S26 has a bore 33 through .thesame fand through which the shaft -I4 extends. A pin 34 extends Vthrough the shaft I4 and is received in a socket35ffor`med in fthe-'element Ze. 'This pin serves as :akey for restraining rotation 'between the :driving selement .26 andthe shaft I4 .and eiectinga Adrive therebetween. The contour ofthe teeth .-32 and '.29 -is curved so that nwhen undue pressure Vis applied to -oneof -the blades, the said v.teeth may slip .out fof 4mesh with one another .in a manner to 'be presently described iin detail `and .permit of relative -rotation 'between the clutch elements.

'The 'blade I'I is constructed with an abutment 36 which is located atthe rearward `end. of said fblade and which extends inwardly toward the 'shaft III and is yconsiderably spaced therefrom. Ti'iis-abutmenthas -a circular surface .L31 whichis -concentric with theaxis of the said shaft. `Operating "in conjunction withthe two blades .III and Ilia -is 1an :adjusting member '33 which is rotatably mounted on the rearmost end of the shaft I'4 and fwhich is -norm'ally separated fromthe nut I6 i by'an intervening space 39. 'The said adjusting `member is in the form of a collar and 'has an ex- -posed.surface 4I which is knurled or otherwise made rough to permit of manually vengagingthe same and rotating the said collarwith respect to the yshaft I 4. The said collar has a'boref'42 through which the shaft I 4 extends and bymeansof which the said collar may rotate and-*operate upon said shaft. The rearmostendfof the bore 42-of1col1ar 38 iserilarged to forma cavity l43 -concentricwith theaxis of the shaft I4. This provides a shoulder '44 at-the foremost end of the said cavity. Afcompression coil spring 45 encircles the shaft I4 and is received within the cavity "43. This spring-is seated at one endaeainst the shoulder f44 vandai;

its other end against the underside of the nut I6. The spring 45 normally urges nut I8 away from the collar 38 tending to force the said collar toward the boss I9 of the hub I3.

At the forward portion of the collar 38 is formed thereon, a number of stops 45, 41, 48, and 45. These stops have cylindrical surfaces 5I which are concentric with the axis of the shaft I4. The said stops are located different distances from the axis of the shaft I4 and the suffaces I thereof are progressively arranged to jointly 'form a surface spiraling inwardly toward the axis of the lsaid shaft. The stops 46, 41, 48, and 49 are radaptedto fbeimoved into a position for engagement with the abutment 36. When the adjust- 4ing member 38 is in the position shown in Fig. 4, abutmentmay engage the stop 46 and the blade Il may then swing to its fullest extent, as shown in full lines in Fig. 1. When the adjusting member 38 is rotated so that the same occupies the positionfshown inFig. 5, the-:stop 41 Aisfin :position to ybe'engaged-,inf the. abutment 436 and'limitsmovenient of theI blade to a position forwardly-.of :that shown rin-idotted llines-in Fig. 1, but frearwandlyof that ,shownin full-lines in said igure. When'the adjusting member 3B .is ,moved to the position shown in Fig. 6, the '.stop y4.9 is inpositionatofhe engaged by the abutment 86. Thefparts v@inaydie so constructed that only a :limited ismall movement of the blade pis xpnssibleiatssuch .-lopation of the adjusting member or so that the blade is held immovable in its :foremost position .as shown 1in Ydotted lines in Fig. il.

For holding the adjusting member 23B in .adjusted position, fthe foremostrend-offthesame is constructed with teeth y52 which @are adapted ilo engage corresponding teeth -5:3 `termed ion the rearward :end o'f the lboss .49 of :hub-I3. Springli serves to urge ,these two portionsof the hub :and adjusting `member 'together and tthereby iholding said teeth in mesh restraining y.relai'fivie rotation between said adjusting :memberand 1hab. These teeth 52 :and .f5.3 are,howeven4 curvedrin :torni :and permit of .rotation of :the isaid adjusting :member when appreciable force :is applied :to :rotate `.the

same. Y

While the-functioning ofthe :propellerhas been described in vconjunction with one :blade only, rit will be comprehended that the'other :blade fhas a corresponding abutment and that the adinsting member has vanother set bf lstops .cooperating therewith seti-iat both bladesattallvtimes coccupy similar positions and :function 'inthe same mnner.

Inasmuch as `the spring 45facts fonzthe'nut M mountedonshaft I4 :andindirectlybnrthe hub |13 .through the :adjusting :member .38, sit .will beroemprehendedthat-the said springserves. fdual purpose. ,In the first instance, it causes :the :clutch element '26 to become engaged :with the 4clutch element 21;and to Ieffect ia drive'fbetween .the '.drive shaft EM and the -hub I3. Inthe secondplacajit .urges ithe 4adjusting member 38 into engagement ithe hub :I3 :and v-restrains rotatable move'- ment ofthe same, This serves rto -hold the .adjusting member in rxed vposition Arelative #to said shaft with one or the :other of fthe-stopsz, :41, 48 .and -49 in engagement with thelabutmentr. However, relative rotation may 'be had between the hub andsha'ft orthehub and adjusting member Iwhen suiiicient force 4'is applied thereto.

The method of using the invention isfobv'ious. The propeller is mounted on the propeller shaft as-shown-in-the`drawings. `Theadjustlng member norm-ally remains -in one dof vits adj ustedpositions and the forward swinging movement of the blades is limited'to the movement afforded when the abutment 36 engages one of the stops on the adjusting'member. If another pitch is desired, the motor is stopped and the adjusting member 38 rotated by means of the knurled portion of the same until the proper stop is in position to be engaged by the abutments on the blades. The spring then holds the same in adjusted position. If during operationof the motor, the blade strikes an object, the pressure on the blade forces the teeth A32 out of engagement with the teeth 29 and allows the clutch to slip. lAs soon as the forceisremoved, the clutch elements become immediately engaged and the drivey is again Veffected between the driving shaftr and the propeller'hub.

The advantages of the invention are manifest. The device' is extremely simple in construction and the hub thereof is compact and of small dimensions so that for a given diameter of blade, a suitable radial length of blade may be procured. The adjusting member is at the rearward end of the propeller where the same is readily accessible for the purpose of adjusting the propeller. A simple rotation of the same is all that is necessary and when released, the adjusting member becomes automatically located in its adjusted position. In the event that the blade strikes a submerged object, the blade is momentarily disengaged from the driving shaft. However, upon passing the object when the blade is again free, a driving connection is again effected between the shaft and the blade without requiring the installation of a new shear pin.

Changes in the specific form of my invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a propeller, a driving member, a driven member and blades pivoted to said driven member, a clutch having a clutch element carried by adjusted positions and resilient means acting between said collar and driving member and urging relative axial movement therebetween to urge said clutch elements in engagement and said collar in adjusted position.

2. In a propeller, a driven shaft, a hub rotatably and axially movable on said shaft, blades pivoted to said hub, the pivots of said blades being positioned so that the pitch of the blades varies upon swinging of the blades, said blades each having an abutment moving radially upon swinging of the blades, a collar rotatable and movable axially relative to said shaft and having stops for engagement with said abutments to hold the blades in adjusted position, a clutch having an element fixed relative to said shaft and an element carried by said hub, said elements becoming engaged upon relative axial movement between said shaft and hub and a spring acting between said shaft and collar and urging relative movement therebetween to hold said collar in adjusted position and said clutch in engagement 3. In a propeller, a driven shaft, a hub rotatably and axially movable on said shaft, blades pivoted to said hub, the pivots of said blades being positioned so that the pitch of the blades varies upon swinging of the blades, said blades each having an abutment moving radially upon swinging of the blades, a collar rotatable and movable axially relative to said shaft and having stops for engagement with said abutments `to rv"hold the blades in adjusted position, a clutch having a clutch element formed in said hub and another clutch element fixed relative to` said shaft, said clutch elements being engageable upon axial movement of the hub relative to the shaft, a spring acting between said shaft and collar and rurging said collar against said hub andsaid hub toward said clutch element on .saidzshaft to causefthe `to be engaged.

collar to engage said hub and said clutch elements 4. In a propeller, a driven shaft, 'a hub rotatably and axially movable on said shaft, blades pivoted to said hub, the pivots of said blades being positioned so that the pitch of Vthelblades varies upon swinging of the blades, said blades each having an abutment moving radially upon swinging of the blades, a collar rotatable' and movable axially relative to said shaft and having stops for engagement with said abutments to hold the blades in adjusted position, a clutch having a clutch element formed in said hub and another clutch element fixed relative to said shaft, said clutch elements being engageable upon axial movement of the hub relative to the shaft, a shoulder formed on said collar, a nut mounted on the end of said shaft and a spring acting between said nut and shoulder and urging said collar against said hub and said clutch elements into engagement.

5. In a propeller, a driven shaft, a hub rotatably and axially movable on said shaft, blades pivoted to said hub, the pivots of said blades being positioned so that the pitch of the blades varies upon swinging of the blades, said blades each having an abutment moving radially upon swinging of the blades, a collar rotatable on said shaft and having a pair of stops extending for a portion of the circumferential extent thereof for engagement with said abutments, said collar when rotated to one position bringing said stops into positions to be engaged by said abutments to hold the blades at one particular pitch and when rotated to another position moving said stops out of the path of movement of said abutments to allow said blades to swing in a manner to have a different pitch and locking means for holding said collar from rotation.

6. In a propeller, a driven shaft, a hub rotatably and axially movable on said shaft, blades pivoted to said hub, the pivots of said blades being positioned so that the pitch of the blades varies upon swinging of the blades, said blades each having an abutment moving radially upon swinging of the blades, a collar rotatable on said shaft and having a pair of stops extending for a portion of the circumferential extent thereof for engagement with said abutments, said collar when rotated to one position bringing said stops into positions to be engaged by said abutments to hold the blades at one particular pitch and when rotated to another position moving said stops out of the path of movement of said abutments to allow said blades to swing in a manner to have a different pitch, said collar and hub having'facing surfaces, locking means formed on said surfaces for holding said collar and hub for relative rotational movement and means for urging relative movement between said collar and hub to bring said surfaces toward one another.

7. In a propeller, a driven shaft, a hub rotat- 92h11,` andaxallymovaoie on saidshait, .blades :pvoted tto hub, -the pivots ni said blades 'bei-nig positioned sothai'. the 'pitch of the -lblades var-ies 'upon swinging of the blades, said .blades eaclrlizwn :ing ari-abutment moving ,radially uponswnging of -the hlades,ra Acollar rotatable on said shaft and *having a pluralityof stops disposed vatdifferent distances from the axis "of said Jshafztgsaid stops rbeing located 'at different 4localities vcircumferentilly of said collar and being'adap'ted Yto selecltively'engage said abutments to fholdthe-:blades in various adjusted `positionsand -means for locking fsaid collar from yrelative movement with respect to said hub.

8. In a, propeller, a driving member, -ad1fiven member, bla-des movably supported-on'saidf'driven member; rel-easable driving :means ybetween driving .member and driven member and :including 1a movable part adapted upon movement in one direction to oppose release of .the rdriven member, adjusting means'for said blades including'arstop, `lockingmeans for *holdingsaiol stop from movefment and including amovablepart movable along substantially `the pathfofzmovementof said rst 'i8 anamed part, .and upon movement in a direction yopposite to the ldenoteddirection of movement of ysaid'irst named part res-training ladjustinganovevment of said 'stop and resilient means acting-between saidpartsandaurging movement-thereof in the respective denoted directions.

EDWARD H. ROUSE.

REFERENCES CITED The vfollowing references are of record in the le Vof this patent:

UNITED STA'I'ES PATENTS Number Name VDate 382,836 Juelson June 28, 1921 133201742 Hewitt Aug.'25, 1931 1;833,843 -Le Parmentier Nov. 24, 1931 1,860,750 Riggs May 31, 1932 2,336,877 Mathews et al Dec.14, 1943 2,371,160 'Everts Mar. '13, 19215 FOREIGN `PATENTS Number Country Date 496,750 Great :Britain Dec. 5, 1938 

